Role of waves in the territorial ecology of Lottia gigantea

Territorial defense in a wide variety of animal species includes extrinsic risks that can have strong influence on the behavior itself. For example, many species are more vulnerable to predation when defending a territory from would-be intruders. The owl limpet, Lottia gigantea, vigorously defends a small (tray-sized) territory from other limpets. Students at Chapman are investigating how territory defense makes limpets more vulnerable, not to predators, but to the dislodging effects of breaking waves. We are testing the tenacity of territorial individuals by pulling them off the rock with a spring scale (see video and photo below). High-speed territorial chases significantly reduce the ability of limpets to cling to the rock, making them much more vulnerable to even relatively small (ca 1-1.5 m) waves.